code: def squared_l2_norm(x):
      x = backend.convert_to_numpy(x)
      return np.sum(x**2)
  
file_path: keras/keras/layers/normalization/unit_normalization_test.py
imports: import numpy
  import pytest
  from keras import backend
  from keras import layers
  from keras import testing
label_desc: Use image node_id 1 for calling a global function with example usage: squared_l2_norm(x) and returns: np